Is it obligatory for the visiting wife to stay overnight for the entire duration of her stay, or is it for each wife to have one night during this period?

The husband must be just among his wives in the division (of nights), even if they are in different countries. He must either go to the absent wife during her days or bring her to him, unless the wife relinquishes her right or refuses to come due to her disobedience (nushuz). If he wishes to divide his time between them while they are in two different countries, the duration can be month by month or as convenient, depending on the proximity of the two countries.

If the second wife comes to the husband's country, he does not stay with her for a full ten days. Rather, he divides his time between her and the first wife night by night, or two or three nights, unless the first wife agrees to him staying for ten consecutive days with the second wife. If the second wife returns to her country, she retains her right to the division.